June 15 (UPI) -- In a nearly unanimous vote, the U.S. Senate on Thursday approved new sanctions against Iran and Russia that also limit President Donald Trump's administration from weakening existing sanctions against Moscow.

In a 98-2 vote, the Senate approved tougher measures against Iran's ballistic missile program, due to the country's support for terrorist groups and its record on human rights.

Sen. Bob Corker, R-Tenn., the author of the bill, told reporters he hoped President Donald Trump would "acknowledge" the near-unanimous support among senators for tougher actions against Iran and Russia.

The measure also included language toughening sanctions against Russia in the wake of their accused efforts to influence the outcome of the 2016 election, converting some of the penalties put in place by former President Barack Obama's administration into law, and forbidding Trump from weakening existing Russia sanctions without first seeking Senate approval.

Senators said the tougher tack against Russia would help force them to ease hostilities against Ukraine, permit a negotiated settlement in the Syrian civil war and dissuade them from attempting to hack U.S. institutions and political groups in the future, as it's widely believed they did during the campaign last year.

"Americans are concerned about Russia's behavior in the Ukraine and Syria and they are concerned about Russia's increased cyber-intrusions," Sen. Mike Crapo, R-Idaho, told NPR. "Many of us on both sides of the aisle feel the U.S. needs to be much stronger in its response to Russia."

Secretary of State Rex Tillerson in testimony on Capitol Hill this week said the Trump administration needs "flexibility" in its negotiations with the Russians and codifying sanctions takes away potential bargaining chips in those talks.

"Essentially, we would ask for the flexibility to turn the heat up when we need to, but also to ensure we have the ability to maintain a constructive dialogue," Tillerson said.

Specifically, the legislation prohibits the U.S. State Department from returning two Russian diplomatic compounds seized by the Obama administration in response to Russia's election hacking.

Members of the U.S. House of Representatives are debating parallel legislation, though it is unclear whether it would be met with the same bipartisan support as it did in the Senate, which would be required in order to survive a potential veto.